氯氰菊酯对海洋卡盾藻的毒性效应

为了解拟除虫菊酯农药对海洋生态系统以及海洋初级生产力的影响,研究了氯氰菊酯对重要赤潮藻类海洋卡盾藻(Chattonella marina)的生长及生化指标的影响.结果表明,低浓度(≤10μg·L-1)的氯氰菊酯对海洋卡盾藻生长具有明显的促进作用,而高于50μg·L-1则产生较明显的抑制效应,但暴露后期会出现一定的超补偿效应.藻细胞内叶绿素a(Chl.a)、可溶性糖和可溶性蛋白含量及超氧化物歧化酶(SOD)活性在暴露初期变化较剧烈,24h或48h后趋于平稳.随着培养(暴露)时间的延长,低浓度暴露组以上指标均呈现先促进后恢复趋势,而高浓度暴露组则呈现先抑制后恢复趋势,丙二醛(MDA)含量随培养(暴露)时间的延长呈先促进后恢复趋势且随氯氰菊酯浓度升高而明显升高.在实验设计浓度下,氯氰菊酯对SOD活性和MDA含量的最低作用剂量为10μg·L-1,而对其他生长和生化指标的最低抑制浓度为50μg·L-1,SOD和MDA可作为监测环境中氯氰菊酯污染的敏感指标.     

Reproductive toxicity and underlying mechanisms of di(2-ethylhexyl) phthalate in nematode Caenorhabditis elegans

DEHP (di(2-ethylhexyl) phthalate) is an endocrine disruptor commonly found in plastic products that has been associated with reproduction alterations, but the effect of DEHP on toxicity is still widely unknown. Using DEHP concentrations of 10, 1, and 0.1 mg/L, we showed that DEHP reduced the reproductive capacity of Caenorhabditis elegans after 72 hr. of exposure. DEHP exposure reduced the reproductive capacity in terms of decreased brood sizes, egg hatchability (0.1, 1 and 10 mg/L), and egg-laying rate (1 and 10 mg/L), and increased numbers of fertilized eggs in the uterus (1 and 10 mg/L). DEHP also caused damage to gonad development. DEHP decreased the total number of germline cells, and decreased the relative area of the gonad arm of all exposure groups, with worms in the 1 mg/L DEHP exposure group having the minimum gonad arm area. Additionally, DEHP caused a significant concentration‐dependent increase in the expression of unc-86. Autophagy and ROS contributed to the enhancement of DEHP toxicity in reducing reproductive capacity, and glutathione peroxidase and superoxide dismutase were activated as the antioxidant defense in this study. Hence, we found that DEHP has a dual effect on nematodes. Higher concentration (10 mg/L) DEHP can inhibit the expression of autophagy genes (atg-18, atg-7, bec-1, lgg-1 and unc-51), and lower concentrations (0.1 and 1 mg/L) can promote the expression of autophagy genes. Our data highlight the potential environmental risk of DEHP in inducing reproductive toxicity toward the gonad development and reproductive capacity of environmental organisms.     

大亚湾核电站运转前后附近地区动物体肝组织、红细胞中超氧物歧化酶活性

本文采用邻苯三酚自氧化法，测定了大亚湾核电站Ⅰ、Ⅱ号机组运转前与后第１年、第２年附近地区动物体肝组织及红细胞中超氧物歧化酶（ＥＣ１．１５．１．１Ｓｕｐｅｒｏｘｉｄｅｄｉｓｍｕｔａｓｅ，ＳＯＤ）活性变化，结果发现Ⅰ、Ⅱ号机组运转后第１年与第２年，鱼类，细鳞（ＴｈｅｒａｐｏｎＪａｒｂｕａ）红细胞与肝组织中ＳＯＤ活性较运转前明显升高（Ｐ＜０．０５），血红蛋白略有下降，肝组织蛋白无明显变化，两栖类动物蟾蜍（Ｂｕｆｏｍｅｌａｎｏｓｔｉｃｔｕｓ）红细胞ＳＯＤ活性运转后亦明显升高（Ｐ＜０．０１），但肝组织中ＳＯＤ活性呈现下降（Ｐ＜０．０５），血红蛋白及肝组织蛋白无明显性变化，本文对其变化可能原因进行了讨论。     

Cu/Zn superoxide dismutase quantification from fetal erythrocytes—an efficient confirmatory test for Down's syndrome after maternal serum screening and sonographic investigations

An enzyme immunoassay especially designed for the quantification of Cu/Zn superoxide dismutase (SOD) in erythrocytes has been applied to measure the SOD of outcomes with high risk for Down's syndrome. From 148 fetuses SOD was quantified from erythrocytes of umbilical vein blood and related to the number of cells, the content of haemoglobin (Hb), and to the haematocrit (Hc). Comparative studies between the SOD content of erythrocytes from the fetuses and their mothers resulted in similar SOD levels (14.09 ± 1.20 for fetal and 14.48 ± 1.63 for maternal cells) with a 1.84-fold smaller variance for fetal cells. The best differentiation between normal fetuses and fetuses with Down's syndrome resulted from the SOD/cell ratio followed by the SOD/Hb ratio. Fixing a cut-off value from the probability density functions that the method results in a specificity of 99.99 per cent, the sensitivity to detect cases of Down's syndrome was 99.71 per cent for the SOD/cell ratio, 70.92 per cent for the SOD/Hb ratio, and 60.21 per cent for the SOD/Hc ratio. Nine cases with Down's syndrome were correctly diagnosed by the SOD/cell ratio determination. Eight of these were confirmed as free trisomy 21 by karyotype analysis and one was found to be a triploidy. The latter was not detected by the SOD/Hb and SOD/Hc ratios because of the one-third higher content of haemoglobin and the larger volume of the erythrocytes which resulted in ratios within the normal range.     

Effects of chitosan on growth of an aquatic plant （Hydrilla verticillata） polluted waters with different chemical oxygen demands

Effects of chitosan on a submersed plant, HydriUa verticillata, were investigated. Results indicated that H. verticillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with high chemical oxygen demand （COD）. Superoxide dismutase （SOD） activity and malondialdehyde （MDA） contents in H. verticillata treated with 0.1% chitosan in wastewater increased with high COD （980 rag/L） and decreased with low COD （63 mg/L）, respectively. Ultrastructural analysis showed that the stroma and grana of chloroplast basically remained normal. However, plant ceils from the control experiment （untreated with chitosan） were vacuolated and the cell interval increased. The relict of protoplast moved to the center, with cells tending to disjoint. Our findings indicate that wastewater with high COD concentration can cause a substantial damage to submersed plant, nevertheless, chitosan probably could alleviate the membrane lipid peroxidization and ultrastructure phytotoxicities, and protect plant cells from stress of high COD concentration polluted water.     

Oxidative stress related enzymes in response to chromium (Ⅵ) toxicity in Oxya chinensis ( Orthoptera : Acridoidae)

The toxic effects of Cr（Vl） on antioxidant enzymes of Oxya chinensis（Orthoptera： Acridoidae） were determined. Changes in the activities of the antioxidant enzymes superoxide dismutase（SOD）, catalase（CAT）, and guaiacol peroxidase（GPx） were measured in O. chinensis insects injected with Cr（VI）. Fifth-nymphs of O. chinensis insects were injected with Cr（VI） with different concentrations （0, 75, 150, 225, 300, 375, 450 mg/kg of body weight）. The results showed that Cr（VI） led to the change of SOD, CAT, and GPx activities at different concentrations, which revealed that： （1） The oxidative stress of SOD increased with the increase of Cr （VI） concentration. （2） With the increase of Cr （VI） concentrations, CAT activities for females increased at lower concentrations, but decreased at higher concentration range, which indicated that antioxidant system of O. chinensis was not influenced by the presence of Cr （VI）. A very similar response to Cr（VI） effect for males indicated that Cr（VI） concentrations were not high enough to damage O. chinensis in terms of CAT. （3） The GPx activity for females increased in all treatments, which revealed that the damage power of Cr（VI） was increased with the increase of Cr（Vi） concentrations in terms of GPx, but the effect was not so remarkable. There was not a consistent trend of GPx activities for males in all treatments of Cr（VI）. Cr（VI）-induced changes in antioxidant enzymes were different for SOD, CAT and GPx, of which the tendency was that activities generally changed with increase of concentrations of Cr（VI） suggesting SOD, CAT, and GPx could serve as indices of oxidative stress to some extent.     

SO2体内衍生物对人血红细胞的氧化损伤及其防护

为了探讨二氧化硫(SO2)对哺乳类细胞的毒性作用及其防护.以SO2体内衍生物-亚硫酸盐和亚硫酸氢盐(分子比为3∶1)及抗坏血酸(维生素C,Vc)单独或同时处理人血红细胞,并测定红细胞过氧化氢酶(CAT)、超氧化物歧化酶(SOD)活性及脂质过氧化(LPO)水平.结果表明,SO2体内衍生物单独处理后,CAT和SOD活性均显著甚至极显著降低,而LPO水平均极显著升高.Vc单独处理后,CAT及SOD活性均有所升高,但差异不显著;而LPO水平除Vc为0.05 mmol·L-1剂量组外,其余各组均极显著降低.0.1 mmol·L-1Vc和不同剂量SO2衍生物共同处理后,Vc使各组CAT、SOD活性均有升高,且Vc也降低了SO2衍生物引起的人血红细胞LPO水平.由此认为,SO2体内衍生物可以使人血红细胞中CAT和SOD的活性降低、LPO水平增高,Vc可起到一定防护作用.     

载铁ACF/Ni阴极电化学体系除藻效能与机制

采用化学浸渍法将Fe@Fe₂O₃纳米线负载在活性炭纤维/泡沫镍上组成Fe@Fe₂O₃/ACF/Ni复合阴极,以钛基铂（Pt/Ti）为阳极,考察载铁量、初始pH值和不同电化学体系对除藻效果的影响,探究无供氧条件下Pt/Ti-Fe@Fe₂O₃/ACF/Ni电化学体系除藻的效能;基于·OH间接检测、铁离子浓度、H₂O₂浓度及pH值的分析和·O₂^-的检测研究Pt/Ti-Fe@Fe₂O₃/ACF/Ni中性电化学体系反应机制.结果表明,当制备阴极阶段投加0.03g FeCl₃×6H₂O,初始藻浓度为0.7×10⁹~0.8×10⁹个/L,电流密度为75mA/cm²,初始pH6.2时,电解60min,该体系除藻率可达到92.3%.在Pt/Ti-Fe@Fe₂O₃/ACF/Ni电化学体系中,Fe@Fe₂O₃/ACF/Ni阴极可通过电化学反应产生大量·OH和·O₂^-,使藻细胞破裂死亡;该体系除藻的主要机理是非均相电Fenton反应.     

双酚A对鲤鱼急性和亚急性毒性的研究

以8月龄至1年龄的鲤鱼为实验对象,研究双酚A(BPA)对鲤鱼(CommonCarp)的急性毒性和双酚A在1/2LD50,1/3LD50,1/4LD50,1/6LD50亚急性浓度下,对鲤鱼肝、肾、鳃中过氧化氢酶(CAT)和超氧化物歧化酶(SOD)的影响.结果表明:双酚A24h,48h,96h的LC50值分别为4.46mg·l-1,4.30mg·l-1,4.25mg·l-1;亚急性毒性指标CAT和SOD对双酚A比较敏感,可作为双酚A污染环境的生物标志物.     

No difference in activity of Sod-1 genotypes of Poa annua to short-term treatment of ambient gaseous organic pollution

Our previous studies indicated that genotypes at locus Sod-1 of Poa annua changed clinally along a gradient of gaseous organic pollution. In the present study, we aimed to know whether there were differential responses of activities of different superoxide dismutase （SOD） genotypes to short-term treatment of ambient gaseous organic pollution. Significant bias from Hardy-Weinberg equibrium was observed on locus Sod-1, and no genotype Sod- l-BB was found. Significantly increased activities were observed in most treatments for genotype Sod-1-AA and in one treatment for genotype Sod-1-AB. However, no significant difference in SOD activities was found between the two genotypes. It was interpreted that fitness difference between the two genotypes was small and treatment duration was too short or extent of ambient organic pollution was too low to lead to differential responses. Other environmental factor effects on activities of superoxide dismutases can also explain the results.